[src/trunk]: src/common/lib/libc/arch/arm/gen Add a routine to create an up t...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/008b645f29da
branches:  trunk
changeset: 783370:008b645f29da
user:      matt <matt%NetBSD.org@localhost>
date:      Mon Dec 17 00:46:14 2012 +0000

description:
Add a routine to create an up to an 128 bitmask returned
in VFP/NEON q0 starting at the rightmost bit (bit 0).

diffstat:

 common/lib/libc/arch/arm/gen/neon_mask.S |  60 ++++++++++++++++++++++++++++++++
 1 files changed, 60 insertions(+), 0 deletions(-)

diffs (64 lines):

diff -r 25a66c8c5482 -r 008b645f29da common/lib/libc/arch/arm/gen/neon_mask.S
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/common/lib/libc/arch/arm/gen/neon_mask.S  Mon Dec 17 00:46:14 2012 +0000
@@ -0,0 +1,60 @@
+/*-
+ * Copyright (c) 2012 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Matt Thomas of 3am Software Foundry.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+#include "assym.h"
+
+#ifdef _ARM_ARCH_7
+
+RCSID("$NetBSD: neon_mask.S,v 1.1 2012/12/17 00:46:14 matt Exp $")
+
+/*
+ * __neon_loading_qword_bitmask(size_t len);
+ *  IN r0 = length of mask in bits
+ * OUT q0 = mask
+ */
+ENTRY(__neon_leading_qword_bitmask)
+       cmp             r0, #64         /* which dword is partial? */
+#ifdef __ARMEL__
+       sublt           r0, r0, #64     /* 1st dword needs MSBs cleared */
+       subge           r1, r0, #128    /* 2nd dword needs MSBs cleared */
+#else
+       rsblt           r0, r0  #64     /* 1st dword needs LSBs cleared */
+       rsbge           r1, r0, #128    /* 2nd dword needs LSBs cleared */
+#endif
+       movge           r0, #0          /* 1st dword needs to left alone */
+       movlt           r1, #64         /* 2st dword needs to be cleared */
+       vmov            d2, r0, r1      /* move dword shifts to SIMD */
+       vmovl.u32       q1, d2          /* 2 U32 -> 2 U64 */
+       vmvn.u64        q0, #0          /* create a mask */
+       vshl.u64        q0, q0, q1      /* shift out unneeded bytes */
+       RET
+END(__neon_leading_qword_bitmask)
+
+#endif /* _ARM_ARCH_7 */